HEPATIC HEMANGIOMA - FINDINGS WITH 2-PHASE CT

PURPOSE: To characterize the appearance of hemangiomas at two-phase dy namic incremental computed tomography (CT) and to determine the cause of contrast material enhancement of adjacent parenchyma in the first s eries. MATERIALS AND METHODS: Contrast-enhanced CT images of 51 hemang iomas in 20 patients were reviewed. Enhancement patterns of hemangioma s in the first series were classified as homogeneous high, peripheral high, and low attenuation; in the second series, as homogeneous high, peripheral high, iso-, and low attenuation. Correlations between arter ioportal shunts and early parenchymal enhancement were evaluated in 45 hemangiomas in the 17 patients who underwent angiography. RESULTS: Th irty-two hemangiomas progressively became enhanced. Four had low and e ight had homogeneous high attenuation in both series. Seven changed fr om homogeneous high to isoattenuation. Early parenchymal enhancement w as well correlated with presence of arterioportal shunt. CONCLUSION Lo w-attenuation hemangiomas and those that changed from homogeneous high to isoattenuation are atypical and difficult to differentiate from ot her neoplasms. Most early parenchymal enhancement is caused by associa ted arterioportal shunts.